I. Field of the Invention
The present invention relates generally to vehicle monitoring systems and more particularly to electronic systems for estimating travel routes taken by a vehicle and the mileage associated therewith, without the need for manual intervention by a vehicle operator.
II. Description of the Related Art
A need is recognized by many in the mobile vehicle environment for tracking vehicle movement or activity in jurisdictions, and particularly for determining miles traveled by a vehicle within a particular jurisdiction. In the commercial trucking industry in particular such information is needed in order to determine the amount of fuel and highway tax liability owed to a state or other pre-defined jurisdiction. The amount of fuel and highway tax owed to each jurisdiction is dependent upon the number of highway miles traveled within that jurisdiction and the amount of fuel purchased within that jurisdiction.
Fuel tax reporting methods in the trucking industry today remain highly inefficient and extremely costly. Most companies devote large amounts of resources to determine their highway usage, to calculate fuel taxes, and to comply with state reporting requirements. Assessment of additional taxes, interest charges, and penalties can make non-compliance extremely costly. The burden is on individual trucking companies to comply with the regulations and to keep detailed records to substantiate what they report.
Heretofore, mileage information has been provided to the trucking company home base by the truck drivers themselves. Most carriers have relied on trip sheets, driver logs, and fuel purchase receipts/bulk storage records for fuel tax reporting. These inputs are subsequently reviewed, and then entered by clerical personnel as the basis for state fuel tax reports. Determining the tax due to each jurisdiction normally involves calculating the average miles per gallon for the entire fleet, calculating the total miles traveled in each state for the vehicle(s) under consideration, and the amount of fuel purchased in each state that the vehicle(s) has traveled. From this, an estimation of the fuel consumed in each state traveled can be determined, which is then compared to actual fuel purchases to determine the tax owed or credited.
Another method of determining miles traveled within a given jurisdiction involves submitting the vehicle's origin, destination, stop-offs and various additional points (i.e. fuel stops, cash advance locations) to a mileage routing package to obtain the "most practical route" traveled and then reporting that as the actual route driven. Carriers using this method are often assessed additional taxes because other documents allow the auditor to dispute the actual route traveled.
Another method of determining state mileage requires read-write transponders at pre-determined locations along the vehicle's travel routes. For example, transponders may be located at each state border, which sense or signal the crossing of state borders by the vehicle and thereupon permit mileage determination by reference to the vehicle's odometer reading at the time of crossing. Cost and privacy issues are primary obstacles for widespread acceptance of this method.
Another known method of jurisdictional mileage determination relies on satellite communications to transmit vehicle position, time that the position was determined, and odometer mileage to a fixed station where it is processed to determine the miles driven in each jurisdiction. An example of such a method is described in International Publication No. WO 96/36018 entitled "METHOD AND APPARATUS FOR DETERMINING TAX OF A VEHICLE" published on Nov. 14, 1996 and assigned to Highwaymaster Communications of Dallas, Tex. The same disclosure was filed in U.S. patent application Ser. No. 08/437,404, filed May 9, 1995. To date, neither patent has issued. The principle drawback of this method is that it requires odometer readings to be transmitted along with each vehicle position. This can be very expensive when using satellite communications because costs are incurred in proportion to the length of the data message. Transmitting odometer readings with each vehicle position transmission results in substantially greater costs to trucking companies, especially companies having very large fleets of vehicles.
Another known method of state mileage determination involves determining and recording the mileage a vehicle travels within a particular state using a GPS receiver, an odometer, a memory device which contains latitude/longitudinal state boundary information, and a processor for determining on a continual basis whether the positional information received from the GPS receiver corresponds to being within a particular state boundary, and recording mileage of the truck when the position and state boundary comparison determines that a change in state boundaries has occurred. An example of such a system is disclosed in U.S. Pat. No. 5,359,528 entitled "SYSTEM FOR ACCURATELY DETERMINING THE MILEAGE TRAVELED BY A VEHICLE WITHIN A STATE WITHOUT HUMAN INTERVENTION" issued Oct. 25, 1994 and assigned to Rockwell International Corporation. The data output, which includes the desired mileage within a particular state, is stored on the vehicle in a storage device. This method requires additional effort and expense to remove the information from the on-board vehicle storage device and load it into a carrier's computer system. A further drawback of this method is that information is not immediately available for a multiplicity of vehicles, such as an entire fleet, nor is information readily available at a single central location, where it would be most helpful, as needed by persons such as a fleet manager. Yet a further drawback of this method is that it requires continuous location monitoring by the GPS receiver and processing unit in order to determine as closely as possible the exact time and odometer mileage when the vehicle crosses a state boundary.